Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cygnus |
Right ascension | 20h 45m 04.09925s [1] |
Declination | +44° 29′ 56.6451″ [1] |
Apparent magnitude (V) | +10.79 [2] |
Characteristics | |
Spectral type | dM1.5 [3] |
B−V color index | 1.491±0.005 [2] |
Astrometry | |
Radial velocity (Rv) | −24.99±0.15 [1] km/s |
Proper motion (μ) |
RA: 434.028
mas/
yr
[1] Dec.: 271.022 mas/ yr [1] |
Parallax (π) | 82.8903 ± 0.0167 mas [1] |
Distance | 39.348 ± 0.008
ly (12.064 ± 0.002 pc) |
Details | |
Mass | 0.423±0.010 [3] M☉ |
Radius | 0.4144±0.0038 [4] R☉ |
Luminosity | 0.0026±0.0003 [3] L☉ |
Surface gravity (log g) | 4.89±0.07 [3] cgs |
Temperature | 3,586±51 [3] K |
Metallicity [Fe/H] | −0.28±0.07 [4] dex |
Rotation | 34.6–48.1 d [4] |
Rotational velocity (v sin i) | 0.46 [5] km/s |
Age | ~3 [6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Gliese 806 is a star in the northern constellation of Cygnus, located about a degree to the southeast of the bright star Deneb. [9] It is invisible to the naked eye with an apparent visual magnitude of +10.79. [2] The star is located at a distance of 39.3 light years from the Sun based on stellar parallax. [1] It is drifting closer with a radial velocity of −24.6 km/s, and is predicted to come to within 30.1 light-years in ~198,600 years. [10] The star hosts two known planetary companions. [4]
The stellar classification of Gliese 806 is dM1.5, [3] which indicates this is a small red dwarf star – an M-type main-sequence star that is generating energy through core hydrogen fusion. It is roughly three [6] billion years old and is spinning with a projected rotational velocity of 0.46 km/s. [5] The star has 42% of the mass and radius of the Sun. It is radiating 0.3% of the luminosity of the Sun from its photosphere at an effective temperature of 3,586 K. [3]
In 1989, Marcy and Benitz detected a periodicity of 416 days in radial velocity variation, inferring the possible presence of a companion with a mass of about 0.011 M☉. [11] However, this candidate object was never confirmed.
More recently, observations by TESS have found a candidate transiting planet with a period of less than a day. [8] In January 2023, this planet was confirmed and a second, non-transiting planet found via radial velocity observations. A third radial velocity signal was also found, but the study was unable to confirm it as having a planetary origin. All known planets are super-Earths, and the inner transiting planet Gliese 806 b is likely to be rocky. [4]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 1.90±0.17 M🜨 | 0.01406±0.00030 | 0.9263237±0.0000009 | — | 87.7+0.6 −0.5 ° |
1.331±0.023 R🜨 |
c | ≥5.80±0.30 M🜨 | 0.0523±0.0011 | 6.64064±0.00025 | — | — | — |
(unconfirmed) | ≥8.50±0.45 M🜨 | 0.0844±0.0017 | 13.60588±0.00065 | — | — | — |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Cygnus |
Right ascension | 20h 45m 04.09925s [1] |
Declination | +44° 29′ 56.6451″ [1] |
Apparent magnitude (V) | +10.79 [2] |
Characteristics | |
Spectral type | dM1.5 [3] |
B−V color index | 1.491±0.005 [2] |
Astrometry | |
Radial velocity (Rv) | −24.99±0.15 [1] km/s |
Proper motion (μ) |
RA: 434.028
mas/
yr
[1] Dec.: 271.022 mas/ yr [1] |
Parallax (π) | 82.8903 ± 0.0167 mas [1] |
Distance | 39.348 ± 0.008
ly (12.064 ± 0.002 pc) |
Details | |
Mass | 0.423±0.010 [3] M☉ |
Radius | 0.4144±0.0038 [4] R☉ |
Luminosity | 0.0026±0.0003 [3] L☉ |
Surface gravity (log g) | 4.89±0.07 [3] cgs |
Temperature | 3,586±51 [3] K |
Metallicity [Fe/H] | −0.28±0.07 [4] dex |
Rotation | 34.6–48.1 d [4] |
Rotational velocity (v sin i) | 0.46 [5] km/s |
Age | ~3 [6] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Gliese 806 is a star in the northern constellation of Cygnus, located about a degree to the southeast of the bright star Deneb. [9] It is invisible to the naked eye with an apparent visual magnitude of +10.79. [2] The star is located at a distance of 39.3 light years from the Sun based on stellar parallax. [1] It is drifting closer with a radial velocity of −24.6 km/s, and is predicted to come to within 30.1 light-years in ~198,600 years. [10] The star hosts two known planetary companions. [4]
The stellar classification of Gliese 806 is dM1.5, [3] which indicates this is a small red dwarf star – an M-type main-sequence star that is generating energy through core hydrogen fusion. It is roughly three [6] billion years old and is spinning with a projected rotational velocity of 0.46 km/s. [5] The star has 42% of the mass and radius of the Sun. It is radiating 0.3% of the luminosity of the Sun from its photosphere at an effective temperature of 3,586 K. [3]
In 1989, Marcy and Benitz detected a periodicity of 416 days in radial velocity variation, inferring the possible presence of a companion with a mass of about 0.011 M☉. [11] However, this candidate object was never confirmed.
More recently, observations by TESS have found a candidate transiting planet with a period of less than a day. [8] In January 2023, this planet was confirmed and a second, non-transiting planet found via radial velocity observations. A third radial velocity signal was also found, but the study was unable to confirm it as having a planetary origin. All known planets are super-Earths, and the inner transiting planet Gliese 806 b is likely to be rocky. [4]
Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
b | 1.90±0.17 M🜨 | 0.01406±0.00030 | 0.9263237±0.0000009 | — | 87.7+0.6 −0.5 ° |
1.331±0.023 R🜨 |
c | ≥5.80±0.30 M🜨 | 0.0523±0.0011 | 6.64064±0.00025 | — | — | — |
(unconfirmed) | ≥8.50±0.45 M🜨 | 0.0844±0.0017 | 13.60588±0.00065 | — | — | — |